LONDON/STOCKHOLM (Reuters) - Iran has released seven of the 23 crew members of the British-flagged tanker Stena Impero that was seized earlier this summer, Sweden’s foreign minister said on Wednesday.

The Swedish-owned Stena Impero was detained by Iran’s Revolutionary Guards on July 19 in the Strait of Hormuz waterway for alleged marine violations, two weeks after Britain detained an Iranian tanker off the territory of Gibraltar. That vessel was released in August.

Sweden’s Foreign Minister Margot Wallstrom said in a statement that the Swedish embassy in Tehran had confirmed that seven of the 23 members had been released.

“I note with relief that part of the crew has been released. I now look forward to the release of the entire ship and the rest of the crew. This is, of course, very gratifying for the crew and their relatives,” Wallstrom said.

The statement did not say which of the crew members had been released or mention their current whereabouts.

Wallstrom said Sweden had been in daily contact with Iran, on a high political level since the vessel was seized.

“It was also an important item on the agenda when I met Foreign Minister Zarif in Stockholm. Although the ship is British-flagged, we have done everything we could to assist, Wallstrom said.

Earlier on Wednesday Erik Hanell, Stena Bulk’s chief executive and president, said in a statement that seven members would be released and that the remaining crew would remain onboard the vessel to safely operate the vessel.

Earlier on Wednesday, Iran’s state television reported that Tehran would free seven of the crew on humanitarian grounds.